Bio-Rad iQ™5 Optical System Software, Version 2.1 - Manual (Page 75)

Section 6 Data Analysis Module
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Fig. 6.22. Melt Curve Chart.
The data in the melt peak chart are derived from the melt curve chart (Figure 6.23).
Fig. 6.23. Melt Peak Chart.
The data in the melt peak chart show the negative rate of change in fluorescence with changing
temperature, that is:
–d(RFU)/dT
Where T is temperature.
In analyzing the melt peak data, the software assigns Begin and End temperatures to each peak
and then calculates an area beneath that curve. The floor of the peak area is specified by the
position of the threshold bar.
In order to be identified as a valid peak, a peak must have a minimum height relative to the
distance between the threshold bar and the height of the highest peak. Therefore, if the
threshold bar is dragged downward, increasing the distance between the threshold bar and the
highest peak, previously unidentified peaks may show up in the spreadsheet as their height
becomes significant in relation to the highest peak. Similarly, dragging the threshold bar up can
cause previously identified minor peaks to drop off the spreadsheet.